Path of Hurricane Matthew moving up the East Coast, October 2016. Sand from federal waters will be used as part of a hurricane and storm damage reduction project for Hutchinson Island, Martin County, Florida. Image credit: NOAA.

The Restoration Center has restored more than 2,000 projects nationwide. You can see what’s happening in your neck of the woods by using the Restoration Atlas, a one-stop review of NOAA’s collective restoration efforts around the country. Visit habitat.noaa.gov.

Ocean Infinity’s fleet of USVs and AUVs (worth close to $50M) is by far the largest UMV asset fleet out there for commercial use. These are just a few of their assets. Photo courtesy of SeaTrepid International, LLC. (SeaTrepid has partnered with Ocean Infinity to develop a multiple autonomous vehicle program.)

Deep ocean temperatures were generally high throughout the Paleocene and Eocene, with a particularly warm spike at the boundary between the two geological epocs around 56 million years ago. Temperatures in the distant past are inferred from proxies (oxygen isotope ratios from fossil foraminifera). "Q" stands of Quarternary. Graph by Hunter Allen and Michon Scott, using data from the NOAA National Climatic Data Center, courtesy of Carrie Morrill.

Sub-zero temperatures in the deep waters of the North Atlantic would significantly hamper the ability of oil-eating bacteria to help the ocean recover from a major oil spill, according to new research.

In the first study of its type, scientists at the University of Aberdeen have tested the ability of oil-degrading microorganisms found in deep water sediments west of Shetland, which is home to several major oil fields.

Microorganisms found in the ocean played an important role in breaking up millions of gallons of oil that spilled into the Gulf of Mexico as a result of the Deepwater Horizon disaster in 2010. The warm waters and abundance of oil-eating bacteria are thought to have significantly aided recovery, however a large amount of oil still reached the seafloor. Oil accumulating in ocean floor sediments can persist for decades and cause harmful effects.

To better understand the oil-degrading abilities of microorganisms in colder waters, scientists analysed samples from west of Shetland and found that degradation was considerably lower at temperatures of 0 °C - similar to those experienced in the deep waters of the North Atlantic and Arctic - than at 5 °C such as those in the Gulf of Mexico.

Results also show that the application of dispersant – a common technique used to help clear major spills - had variable effects, suggesting care should be taken when deciding whether to apply these chemicals as part of an oil spill response.

Overall, the study has provided evidence that the environmental consequences of a major spill in colder waters would last far longer than other deep water drilling environments.

Professor Ursula Witte is the senior author of the study, co-authored by Professor Jim Anderson, Evangelia Gontikaki and Dr Robert Ferguson, who is now at the University of Essex. The study has been published in Scientific Reports.

Professor Witte said: “Depleting oil reserves has forced the industry to explore progressively deeper waters, and the dramatic shrinking of Arctic sea ice means that previously inaccessible reserves are now considered for exploration.

“Understanding the environmental implications of an oil spill in the cold and deep ocean is therefore urgent to improve our response to a potential spill.

“This study is the first to confirm that hydrocarbon degradation in sediments at 0 °C is significantly slower than at 5 °C.

“The fact that certain hydrocarbons we tested did not show any detectable levels of degradation at 0 °C suggests that the impact of oil contamination at near zero or sub-zero temperatures would have a severe long term impact on the marine environment.”

Dr Ferguson added: "The results also show that we do not fully understand the consequences of using dispersants in the cold or deep ocean. Careful consideration is needed before this is adopted as a strategy for cleaning up an oil spill in the deep sea.”

The full paper – The Variable Influence of Dispersant on Degradation of Oil Hydrocarbons in Subarctic Deep-Sea Sediments at Low Temperatures (0–5 °C) is available online here.